1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device and fabricating method thereof. Although the present invention is suitable for a wide scope of applications, it is particularly suitable for adjusting a quantity of liquid crystals in the liquid crystal display device fabricated by liquid crystal dropping method.
2. Discussion of the Related Art
Generally, liquid crystal display (LCD) devices are used as flat panel display devices because of their thin screens and low operational voltage which give LCD panels to consume less power and an excellent portability, making them suitable for a variety of applications including notebook computers, monitors, aerospace applications and the like.
This liquid crystal display device is in detail explained with reference to the attached drawing as follows.
FIG. 1 is an exploded perspective diagram of a liquid crystal display device according to a related art.
Referring to FIG. 1, a liquid crystal display device according to a related art consists of a lower substrate 10, an upper substrate 20 facing the lower substrate 10 leaving a prescribed distance therebetween, and a liquid crystal layer (not shown in the drawing) provided between the lower and upper substrates.
A gate line 12 and a data line 14 are formed on the lower substrate 10 to define a pixel area by crossing with each other. A thin film transistor T used as a switching device is formed at the crossing of the gate and data lines 12 and 14. A pixel electrode 16 connected to the thin film transistor T is formed in the pixel area.
A shield layer 22 is formed on the upper substrate 20 to cut off light from leaking from outside the pixel area. A color filter layer 24 of red (R), green (G) and blue (B) is formed on a part corresponding to the pixel area to represent colors. Furthermore, a common electrode 26 is formed on the color filter layer 24.
The above-configured liquid crystal display device is fabricated by preparing the lower and upper substrates and forming a liquid crystal layer between the prepared substrates. In this case, the liquid crystal layer is formed between both of the substrate by a vacuum injection method or a liquid crystal dropping method.
The vacuum injection method is carried out by forming a sealant having one inlet on one of the two prepared substrates, bonding the two substrates together and injecting liquid crystals into a space between the two substrates via the inlet.
The liquid crystal dropping method is carried out by forming a sealant having no inlet on one of the two prepared substrates, dropping liquid crystals on the substrate and bonding the two substrates together.
As a size of a substrate increases, it takes so much time in injecting liquid crystals by the vacuum injection method as to reduce manufacturing productivity. So, the liquid crystal dropping method is more suitable for large-scale substrates. However, in the liquid crystal dropping method it is difficult to calculating the proper quantity of liquid crystals.
In particular, the liquid crystal dropping method differs from the vacuum injection method in dropping a prescribed quantity of liquid crystals after calculating a liquid crystal quantity by considering a cell size, a cell height and the like. It is substantially difficult to calculate a precise quantity of liquid crystals due to various factors.
If the liquid crystal quantity calculated is too small, a filling-failure area of liquid crystals is generated within a liquid crystal display panel. If the liquid crystal quantity calculated too large, an over-filling area is generated within a liquid crystal display panel, lowering the quality of the display.
Many efforts have been made to minimize the generation of the insufficient or excessive filling of liquid crystals in various ways. Once the insufficient or excessive filling of liquid crystals takes place, there is no way in the related art to correct the insufficient or excessive filling of liquid crystals. If the filling error is serious, the corresponding panel must be discarded, which is not economical.